Hesketh Out Marsh close up

Over the past few months I've been involved in a study of invertebrates at RSPB Hesketh Out Marsh and Crossens Marsh, on the Ribble estuary. The study involves the use of pitfall traps to catch insects and other invertebrates at the two sites, and these are then taken back to the lab where I identify and count them, so that a comparison can be made. Today we went out to set the traps in order to get some more samples.


This is the "bus shelter" hide at Hesketh Out Marsh, and is about as close as most visitors can get to the marsh.


However, armed with the necessary permission, relevant wading gear and collecting equipment, we headed out into the centre of the marsh.


Saltmarsh may seem like the sort of habitat which has remained unchanged since the dawn of time, one of the last wild places untouched by the hands of Man, but Hesketh Out Marsh is actually a vision of the future rather than an image of the past.

Up until 1980, this was indeed saltmarsh, but then a sea wall was built around the land, and it was converted to farmland. In 2006 the RSPB bought the land and breached the sea wall, allowing the sea to flood in again, which in turn allowed the saltmarsh to begin to return. The photo above shows the breach, which has now been made much wider than it initially was, by the actions of the sea. Not only does this provide a great new habitat for many saltmarsh creatures, it is also a form of managed realignment in the face of rising sea levels due to climate change.


This photo is also taken next to the breach.


Using a special tool, we sink pitfall traps into the ground, to catch ground dwelling invertebrates. The catches are usually dominated by spiders, ground beetles, rove beetles (staphs), water beetles, water bugs, amphipods, woodlice and springtails.


A lid is placed over the trap, using the two sticks to leave a 10mm gap. This is to stop larger creatures getting in, such as small mammals. The area is covered by the sea on spring high tides, which means that we are only able to set the traps during neap tides, since they need to be left out for a few days.


The sea really carves out the land, and at the moment Hesketh Out Marsh is a very dynamic and changing place.


It was a glorious day to be out on the marsh, with the calls of Redshank never far away. Shelduck were calling and chasing each other across the marsh, and the song of Skylarks filled the air, heralding the arrival of spring!